Interest in the use of extruded ceramic monoliths as catalyst supports is growing in the chemical process and refining industries, since such monoliths provide both large geometric surface area and low pressure drop. The characteristics of honeycomb structures are beneficial for reactions currently obtained in trickle bed and slurry reactors. Also, monolith reactors can be used in either counter-flow or co-current flow in the so-called Taylor or slug flow regimes.
The extruded honeycomb monoliths can be catalytically active or coated with a wash coating and catalyzed with an active material. However, because present extrusion manufacturing limitations prevent the production of large monoliths, it is necessary to assemble a plurality of smaller monoliths such as by cementing the parts together in order to fabricate large monolithic structural shapes.
A major problem encountered with the use of such monolithic honeycomb structures as catalyst supports in reactors is that of vibration and differential expansion between the monoliths and the reactor walls. The honeycomb ceramic substrates, being brittle, are subject to damage and deterioration from both expansion and vibration, and the present invention provides unique support structures to compensate for and alleviate such problems.
The prior art has not really addressed these problems, although U.S. Pat. No. 5,108,716 discloses a catalytic converter for an automobile having a first and second monolith in a row. U.S. Pat. No. 4,195,064 discloses a bed-type catalytic reactor having horizontal beams mounted for movement relative to vertical columns. Finally, European Patent Specification 0226306B1 discloses a complex arrangement of ledges and projections that function to support and interlock adjacent ceramic structures used as catalyst supports.